Application of the DLC film to machine parts such as automotive parts has been in progress due to its high hardness, low friction, low attackability to a mating member, or the like. In the meantime, the DLC film has a large internal stress, to thus be peeled off from the base material easily. Therefore, such an interface control as to form the intermediate layer between the base material and the DLC layer has been conventionally performed, to thereby secure adhesion between the base material and the DLC film.
As such a prior art relating to the intermediate layer as described above, there has been described in Patent Document 1 a method of forming an intermediate layer composed of a Ti layer and a TiC layer between a base material and a DLC layer. In Patent Document 1, in order to avoid an effect on the base material, the intermediate layer is formed on a surface of the base material by using a PVD method that enables film formation at low temperature.